2 * include/linux/ktime.h
4 * ktime_t - nanosecond-resolution time format.
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
9 * data type definitions, declarations, prototypes and macros.
11 * Started by: Thomas Gleixner and Ingo Molnar
15 * Roman Zippel provided the ideas and primary code snippets of
16 * the ktime_t union and further simplifications of the original
19 * For licencing details see kernel-base/COPYING
21 #ifndef _LINUX_KTIME_H
22 #define _LINUX_KTIME_H
24 #include <linux/time.h>
25 #include <linux/jiffies.h>
28 /* Nanosecond scalar representation for kernel time values */
32 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
33 * @secs: seconds to set
34 * @nsecs: nanoseconds to set
36 * Return: The ktime_t representation of the value.
38 static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
40 if (unlikely(secs >= KTIME_SEC_MAX))
43 return secs * NSEC_PER_SEC + (s64)nsecs;
46 /* Subtract two ktime_t variables. rem = lhs -rhs: */
47 #define ktime_sub(lhs, rhs) ((lhs) - (rhs))
49 /* Add two ktime_t variables. res = lhs + rhs: */
50 #define ktime_add(lhs, rhs) ((lhs) + (rhs))
53 * Same as ktime_add(), but avoids undefined behaviour on overflow; however,
54 * this means that you must check the result for overflow yourself.
56 #define ktime_add_unsafe(lhs, rhs) ((u64) (lhs) + (rhs))
59 * Add a ktime_t variable and a scalar nanosecond value.
62 #define ktime_add_ns(kt, nsval) ((kt) + (nsval))
65 * Subtract a scalar nanosecod from a ktime_t variable
68 #define ktime_sub_ns(kt, nsval) ((kt) - (nsval))
70 /* convert a timespec64 to ktime_t format: */
71 static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
73 return ktime_set(ts.tv_sec, ts.tv_nsec);
76 /* Map the ktime_t to timespec conversion to ns_to_timespec function */
77 #define ktime_to_timespec64(kt) ns_to_timespec64((kt))
79 /* Convert ktime_t to nanoseconds */
80 static inline s64 ktime_to_ns(const ktime_t kt)
86 * ktime_compare - Compares two ktime_t variables for less, greater or equal
91 * cmp1 < cmp2: return <0
92 * cmp1 == cmp2: return 0
93 * cmp1 > cmp2: return >0
95 static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
105 * ktime_after - Compare if a ktime_t value is bigger than another one.
109 * Return: true if cmp1 happened after cmp2.
111 static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
113 return ktime_compare(cmp1, cmp2) > 0;
117 * ktime_before - Compare if a ktime_t value is smaller than another one.
121 * Return: true if cmp1 happened before cmp2.
123 static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
125 return ktime_compare(cmp1, cmp2) < 0;
128 #if BITS_PER_LONG < 64
129 extern s64 __ktime_divns(const ktime_t kt, s64 div);
130 static inline s64 ktime_divns(const ktime_t kt, s64 div)
133 * Negative divisors could cause an inf loop,
137 if (__builtin_constant_p(div) && !(div >> 32)) {
139 u64 tmp = ns < 0 ? -ns : ns;
142 return ns < 0 ? -tmp : tmp;
144 return __ktime_divns(kt, div);
147 #else /* BITS_PER_LONG < 64 */
148 static inline s64 ktime_divns(const ktime_t kt, s64 div)
151 * 32-bit implementation cannot handle negative divisors,
152 * so catch them on 64bit as well.
159 static inline s64 ktime_to_us(const ktime_t kt)
161 return ktime_divns(kt, NSEC_PER_USEC);
164 static inline s64 ktime_to_ms(const ktime_t kt)
166 return ktime_divns(kt, NSEC_PER_MSEC);
169 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
171 return ktime_to_us(ktime_sub(later, earlier));
174 static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
176 return ktime_to_ms(ktime_sub(later, earlier));
179 static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
181 return ktime_add_ns(kt, usec * NSEC_PER_USEC);
184 static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec)
186 return ktime_add_ns(kt, msec * NSEC_PER_MSEC);
189 static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
191 return ktime_sub_ns(kt, usec * NSEC_PER_USEC);
194 static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec)
196 return ktime_sub_ns(kt, msec * NSEC_PER_MSEC);
199 extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
202 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
203 * format only if the variable contains data
204 * @kt: the ktime_t variable to convert
205 * @ts: the timespec variable to store the result in
207 * Return: %true if there was a successful conversion, %false if kt was 0.
209 static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
210 struct timespec64 *ts)
213 *ts = ktime_to_timespec64(kt);
220 #include <vdso/ktime.h>
222 static inline ktime_t ns_to_ktime(u64 ns)
227 static inline ktime_t ms_to_ktime(u64 ms)
229 return ms * NSEC_PER_MSEC;
232 # include <linux/timekeeping.h>
233 # include <linux/timekeeping32.h>